I visited a friend recently and he uploaded Linux on my laptop. He uploaded many programs from his laptop unto mine using a terminal. To do this he had to add a very long code from his laptop onto my laptop using my terminal and visa versa from mine to his using his terminal to give him remote access through his wifi to my laptop. I am new to the Linux OS and still have much to learn so please bear with my ignorance.
My question: How do I find that long code and remove it and what would be the right terminology to describe what he did on my laptop? Did he merely create a network group through terminal or did he open a kind of a door which only he knows of?
$ dpkg -s openssh-server | grep Status
Status: install ok installed
dpkg -s openssh-server | grep Status
to your question. This checks whether this package is installed on your system, ssh is the way to set up a connection like you describe. If it is installed and you don’t want it to be, simply remove it withsudo apt remove openssh-server
and restart.